Optical Waveguide Mode Field Diameter Measurement Method Based on Near-field Fiber Probe End-face Scanning

The proposed method is based on the near-field fiber end-face scanning of the optical waveguide mode field diameter measurement method. Using the scanning fiber probe to scan the optical waveguide end-face Y direction and Z direction, to obtain the coupling efficiency distribution of the corresponding direction. Combining the mode field distribution function and relative motion of the fiber probe and the optical waveguide, the scanning process is modeled mathematically. The relationship between the Gaussian distribution of the coupling efficiency curve and the mode field distribution of the optical wave is deduced. The mode field diameter of the optical waveguide can be inverse calculated accordingly, and the arbitrary mode field distribution characteristics can be obtained by deconvolution method. A near-field optical waveguide mode field measurement system was built to measure the coupling efficiency and dislocation relationship between fiber and fiber, fiber and waveguide. And accordingly giving the mode field diameters in the Y and Z directions of the optical waveguide mode field. The feasibility and validity of the optical waveguide mode field diameter measurement method based on near-field fiber end-face scanning are experimentally verified.